“We’re closer to sending human beings to the Red Planet than ever before in human history,” Bolden told a meeting at the Center for American Progress in Washington, DC.

In a preparatory mission for the manned Mars landing, Bolden explained, NASA also plans to send an unmanned module in 2020.

“[NASA will send a] new rover to the red planet in 2020 that will help us prepare for [a] human mission,” Bolden said.

The unmanned mission would be designed to send Mars rocks back to Earth for direct scientific examination, he told the audience.

Bolden also said that when the 2030 manned mission arrived on the Martian surface, the astronauts would not have to build their own base because it would already have been constructed underground for them by robots sent in advance.

“We are going to send a team of robots in. We will send the robotic precursors in. … That’s what I mean about collaboration between humans and robotic technology,” he pointed out.

Bolden explained an underground base on Mars would have many advantages for human survivability over one constructed on the planet’s surface.

“I think we will probably live under ground for the most part. It gets rid of the need for above ground shielding,” he stated.

Bolden commanded two US space shuttle missions and was the pilot on two in his previous career as an astronaut. He has been NASA’s chief administrator since July 2009.

Before and after his time as an astronaut, Bolden served in the US Marine Corps and rose to the rank of major general.